It’s too soon to tell whether an association exists between Parkinson’s disease and lifestyle choices such as smoking or consumption of alcohol, coffee or tea, according to a new review published in the Journal of Parkinson’s Disease.
Researchers looked at literature from 2000 to 2014 and determined that the studies examined had flaws that could explain their varying and, often, conflicting findings. “These included selection or self-selection of controls, difficulties in retrospective assessment of alcohol consumption, differences in the lengths of follow-up periods, and inconsistent definitions of drinkers and non-drinkers,” said lead investigator Silvana Bettiol, Ph.D., M.P.H., of the University of Tasmania School of Medicine in Tasmania, Australia.
In addition, Bettiol said, in studies in which alcohol consumption and Parkinson’s disease incidence were accurately measured over time, only non-significant associations were found, further supporting the argument that various limitations and biases affected many of the studies.
Including more people in prospective studies could result in more reliable results, Bettiol said. “Improvements to reporting of studies by investigators particularly with respect to sample size and power would help others interpret the epidemiological significance of any findings,” she said. “Most of the studies proved to be preliminary, and improving statistical power to detect joint effects was encouraged.”
